Spray nozzle and a sprayer including such a nozzle

ABSTRACT

A nozzle for spraying a fluid comprises an outlet duct (3, 4) opening out into a swirling chamber (5) in the center of an annular surface (10), the chamber being closed by an end wall (6) which is pierced by an outlet orifice (7) and which includes an inside face (6a) provided with swirling grooves (80. The swirling chamber (50 is partially filled by a core (9), the core leaving at least one lateral passage (11) empty, putting the swirling groove into communication with the outlet duct. The spray nozzle also includes a valve adapted to close the outlet duct. The core is a substantially circularly cylindrical elastomer part which is resiliently compressed axially against the end wall (6) of the swirling chamber and the annular surface (10), the core (9) cooperating with the annular surface to constitute the valve, and the core being pressed against the nd wall, thereby isolating the swirling grooves (8) so that they do not communicate with one another between the outlet orifice (7) and the lateral passage (11) left empty by the core (9).

BACKGROUND OF THE INVENTION

The present invention relates to a spray nozzle, and to a sprayerincluding such a nozzle.

Miniaturized sprayers for fluids (liquids or semi-liquids) such asperfumes, cosmetics, or pharmaceuticals, generally comprise a member forcontrolling emission of the fluid substance (a pump or a valve) that isconnected via an outlet duct to a spray nozzle which atomizes the fluidsubstance into very fine droplets having a diameter of a few tens ofmicrons.

In such sprayers, a known problem is to avoid the fluid drying oroxidizing in the outlet duct between two uses, and also to avoid thefluid seeping out from the spray nozzle between two uses. DocumentFR-A-2 635 084 teaches solving that problem by using a valve memberwhich closes the outlet duct.

Also, the spray nozzle disclosed in document FR-A-2 635 084 includes, asdo many spray nozzles, a swirling chamber closed by an end wall andfilled in part by a core. The end wall includes an outlet orifice andnon-radial internal grooves converging towards the outlet orifice. Thecore disposed inside the swirling chamber is generally substantially incontact with the end wall so that the fluid emitted under pressure isconstrained to follow the non-radial grooves prior to reaching theoutlet orifice. Because of the small section of the grooves, the fluidsubstance is highly accelerated, and in addition the orientation of thegrooves imparts swirling motion thereto such that the fluid is veryfinely divided when it reaches the outlet orifice.

However, a small gap may remain between the core and the end wall of theswirling chamber, such that the fluid does not pass along the grooves,thereby degrading the quality of the spray. The gap may be due tomanufacturing tolerances, to creep of parts made of plastics material,etc.

From documents EP-A-0 117 898 and U.S. Pat. No. 4,273,290, it is knownto isolate such grooves by members comprising a valve disk whichco-operates with a surface to form an outlet valve and a disk to isolatethe grooves at the outlet of the nozzle. The two disks areinterconnected by an S-shaped spring which enables the valve disk tomove away from its seat under the effect of fluid pressure. Thosemembers thus comprise three distinct elements, namely two disks and onespring, even if the member in document 02 is molded as a single part.

However, the cores disclosed in those documents suffer from the drawbackof being difficult to mold because of their geometrical complexity.Also, they leave a large dead volume inside the chamber, thereby leadingto the fluid which stagnates therein being spoiled.

SUMMARY OF THE INVENTION

An object of the present invention is to remedy that drawback.

The present invention thus provides a nozzle for spraying a fluid, thenozzle comprising an outlet duct suitable for receiving said fluid andopening out into a distribution chamber in the center of an annularsurface, said chamber being closed by an end wall which is pierced by anoutlet orifice and which includes an inside face provided with groovesin communication with the outlet orifice, said chamber being partiallyfilled by a core which extends axially between a front face close to theend wall and a rear face remote from the end wall, the core leavingempty at least one lateral passage putting the grooves intocommunication with the outlet duct, the spray nozzle also comprising avalve adapted to close the outlet duct except during periods when saidfluid is being sprayed, and to open under the effect of fluid arrivingin the outlet duct, the core co-operating with the annular surface toconstitute said valve, said rear face of the core being adapted to bearwith sealed contact against said annular surface, the nozzle beingcharacterized in that the core is a substantially circularly cylindricalelastomer part which is resiliently compressed between the end wall ofthe distribution chamber and said annular surface.

Preferably, the grooves are oriented in non-radial manner relative tothe outlet orifice, said front face of the core being pressed againstthe end wall, thereby isolating the swirling grooves such that theswirling grooves do not communicate with one another between the outletorifice and said at least one lateral passage left empty by the core, inorder to impart swirling motion to said fluid. In this way, the core iskept in contact against the end wall by its own resilience, therebyeliminating the above-mentioned gap, and simultaneously it acts as avalve member for closing the outlet duct. When the fluid arrives underpressure in the outlet duct, the rear face of the core is moved awayfrom its annular thrust surface by axial elastic deformation under theeffect of the pressure, thereby pressing the front face of the core evenmore firmly against the end wall of the swirling chamber.

In addition, because of its simple shape, the core is easy tomanufacture. A core of the invention is obtained from a simple elastomercord of circular section which is cut to the desired thickness. It iseasy to match different sizes of swirling chamber by taking a cord ofappropriate section from which a slice is cut corresponding to thelength of the chamber.

Another advantage of the core of the invention comes from the fact thatthe core fills the swirling chamber leaving very little dead volume.Thus, the volume of fluid that stagnates in the swirling chamber issmall, and as a result there is very little deterioration due tooxidation or drying. The core can be adapted so that it leaves acylindrical annular lateral passage of very small section.

In one embodiment, the front face of the core includes a projectingportion which penetrates into the outlet orifice. This restricts thedead volume inside the spray orifice.

Advantageously, said annular surface is conical, with its concave sidefacing the core, and the rear face of the core is circular. The zone insealed contact between the rear face of the core and the annular thrustsurface is then a rather narrow outer annular zone. In a variant, saidannular surface is a sealing ridge disposed close to the outside of therear face of the core.

The core may be molded in thermoplastic elastomer (TPE), therebyfacilitating manufacture and making it possible to obtain sufficientflexibility.

Centering means may be provided for positioning the core relative to theoutlet duct and to the outlet orifice.

In another embodiment, the core is a disk that is elastically deformableby bending, and that is prestressed between the annular surface and theend wall, the annular contact of said disk with the annular surfacebeing of a diameter that is smaller than the diameter of the contact ofthe disk with the end wall such that the pressure exerted by the fluidinside the outlet duct deforms the disk by bending its peripherallyouter portion, thereby breaking contact with the annular surface. Thecore is deformed by bending instead of by axial compression. There is atilting effect under the pressure of the fluid, while still ensuringintimate contact on the swirling channels. This form of core is betteradapted to valve members for use with a gel or with a cream, withoutspraying.

Advantageously, the core may be of narrowed section at an intermediateposition along its axial length, thereby giving it greater axialflexibility.

The invention also provides a fluid sprayer comprising a spray nozzleaccording to any preceding claim, and a pump which comprises:

a cylindrical pump chamber;

a piston which slides in the pump chamber;

an inlet orifice which communicates with the pump chamber via an inletvalve; and

a delivery duct which is permanently in communication with the outletduct of the spray nozzle.

The spray pump is considerably simplified since it no longer includes adelivery valve: it is the core of the nozzle in co-operation with theannular thrust surface that constitutes the delivery valve. Because thecore is continuously resiliently compressed, this delivery valve opensonly when sufficient predetermined pressure exists in the pump chamberto move it away from its annular thrust surface: the sprayer is thus ofthe "compression" type and guarantees excellent spraying.

Document EP-A-0 378 935 describes a pump whose delivery valve member isconstituted by an axially deformable resilient part disposed in theoutlet duct in the vicinity of the outlet orifice. However, that pumpdoes not include a spray nozzle since it is designed to dispenseophthalmological medication in the form of one drop per actuation.

In one embodiment, the piston is controlled by an actuator rod in whichthe delivery duct is formed, the pump including a spring exerting areturn force on the piston, and a pushbutton is mounted on the actuatorrod to move the piston against the force of the spring, the pushbuttonincluding said spray nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention appear from thefollowing detailed description of an embodiment of the invention givenby way of non-limiting example with reference to the accompanyingdrawings.

In the drawings:

FIG. 1 is a section view through a pushbutton including a spray nozzleof the invention;

FIGS. 1a and 1b are detail views of two variants of the FIG. 1pushbutton;

FIG. 2 is a section view of the core of the spray nozzle of FIG. 1;

FIG. 3 is a section view of a variant of the FIG. 2 core;

FIG. 4 is a section view on line IV--IV of FIG. 1;

FIG. 5 is a section view of a pump on which the pushbutton of FIG. 1 canbe mounted; and

FIG. 6 is a section view of a second embodiment of a spray nozzle madein accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a pushbutton 1 adapted to be mounted on an actuator rod 2of a pump or a valve for dispensing a fluid which may be a liquid or asemi-liquid, such as a perfume, a cosmetic, or a medicine, or some otherfluid. The pushbutton 1 forms a portion of a small spray assemblyadapted to be held in the hand and enables the pump or valve to beactuated by means of a finger, even though automatic actuation is alsoconceivable without going beyond the ambit of the invention.

The pushbutton 1 is generally molded in plastics material. It includes aduct 3 in which the actuator rod 2 is engaged. The actuator rod 2 has acentral channel 2a that enables the fluid to be emitted and thatcommunicates with the duct 3. The pushbutton also includes a swirlingchamber 5 which opens out sideways to the outside of the pushbutton. Theswirling chamber 5 has a circularly cylindrical side wall 20 and an endwall 10 pierced by a central orifice 4 which communicates with the duct3. In this case the end wall 10 is conical in shape, with its concaveside facing the chamber 5. It should be observed that the chamber 5could equally well be disposed in line with the duct 3 instead of beingdisposed laterally.

The chamber 5 receives a socket-shaped part 21 molded out of plasticsmaterial and referred to as a spray insert. The insert 21 comprises anend wall 6 and a side wall 22. To prevent the insert 21 from beingexpelled from the chamber 5 by the pressure of the fluid, it is firmlysecured to the pushbutton 1. In the example shown, the side wall 22 ofthe insert includes an outer annular rib 23 that is barb-shaped and issnapped by force into a complementary groove in the side wall of thechamber 5. The end wall 6 of the insert 21 thus closes the open end ofthe swirling chamber 5. Nevertheless, the end wall 6 of the insert ispierced by a central outlet orifice 7 of very small diameter, having anenlarged portion that flares towards the inside of the chamber 5. Theend wall 6 of the insert also includes an inside face 6a in whichnon-radial swirling grooves 8 are formed that extend between theenlarged portion of the outlet orifice and the outer periphery of theinside face 6a. As can be seen in FIG. 4, the grooves 8 are oriented toimpart swirling motion to the fluid on arrival in the flared portion ofthe orifice 7.

With reference again to FIG. 1, an elastomer core 9 is placed in theswirling chamber 5, being resiliently compressed against the end wall 6of the insert and the end wall 10 of the swirling chamber. The core 9 isadvantageously made of thermoplastic elastomer (TPE), e.g. Kraton®(Shell). This type of elastomer has the advantage of acceptingconsiderable elastic deformation and of being suitable for injectionmolding, thereby facilitating manufacture thereof.

As shown in FIG. 2, the core 9 is a circularly cylindrical part whichextends axially between a rear face 9b and a plane front face 9a that isoptionally provided with a central projection 9c that penetrates intothe enlarged portion of the outlet orifice. In the example shown, thecore 9 may typically have a diameter of 2.5 mm to 5 mm, and a length of3 mm to 10 mm. In special circumstances, its length may possibly go downto 1 mm or up to 20 mm to 30 mm. Nevertheless, these dimensions aregiven purely by way of non-limiting example.

When the core 9 is mounted in the pushbutton 1, as shown in FIG. 1, theinitially plane rear face 9b is deformed by elastic compression againstthe end wall 10 of the chamber 5, with deformation taking place in anouter annular zone 9d, thereby guaranteeing excellent sealing. Thisensures that the duct 3 is closed between two squirts. Advantageously,as shown in FIG. 1, the annular zone 9d does not extend radially all theway to the central orifice 4 so that fluid under pressure coming fromthe duct 3 exerts its pressure on a maximum area of the rear face 9b ofthe core. As shown in FIG. 1a, the core 9 may include anoutwardly-directed flange 31 on its rear face 9b so as to maximize thearea of the rear face 9b on which the pressure of the fluid coming fromthe duct 3 acts. In FIG. 1a, the flange 31 is received between a rearend of the side wall 22 of the insert and the end wall 10 of the chamber5. In a variant, as shown in FIG. 1b, the end wall 10 of the chamber 5may include an annular sealing ridge 30 disposed around the orifice 4 inthe vicinity of the outside diameter of the core 9, and against whichthe rear face 9b of the core presses: the fluid under pressure from theduct 3 can thus exert its pressure over the entire area of the rear face9b situated inside the ridge 30. In this variant, the end wall 10 of thechamber 5 may be flat. In addition, the core 9 may also include anoutwardly directed flange 31 as in FIG. 1a: the ridge 30 is then placedfacing the flange 31, thereby further increasing the area of the rearface 9b of the core against which the pressure of the fluid from theduct 3 acts.

The front face 9a of the core is pressed in sealed contact against theinside face 6a of the end wall of the insert, and an annular space 11 isleft free between the side wall 22 of the insert and the core 9. Thus,when the fluid is emitted under pressure and penetrates into the duct 3,it pushes away the rear face 9b of the core, by causing the core todeform elastically in an axial direction. The fluid then flows towardsthe annular space 11 and then along the swirling grooves 8 prior tobeing sprayed through the outlet orifice 7.

The side wall 22 of the insert 21 may optionally include internal axialribs 18 or other portions in relief for positioning the core 9. In avariant, axial ribs or other portions in relief could be formed on thecore 9.

As shown in FIG. 3, in order to increase its axial flexibility, the core9 may optionally include a central portion 24 of narrower section.

FIG. 5 shows a pump 12 for operating together with the pushbutton ofFIG. 1. The pump 12 comprises a pump body 25 molded in plastics materialand defining a cylindrical pump chamber 13. The pump chamber 13 extendsbetween an open end 25a and an end 25b provided with an inlet orifice15. The inlet orifice 15 communicates with a tank of said fluid (notshown) either directly or else via a dip tube (not shown). A piston 14molded in plastics material slides inside the pump chamber 13. Thepiston 14 has an actuator rod 2 which projects through the open end ofthe pump body and which is pierced by a central channel 2a that opensout into the pump chamber 13. The inlet orifice 15 is provided with aninlet valve made up of a valve member 16 of elastomer adapted to bear insealed manner against a valve seat 17 formed around the inlet orifice15. The inlet valve allows fluid only to enter the pump chamber 13. Thevalve member 16 is kept close to the valve seat 17 by a carrier 26.

A helical metal return spring 19 is mounted between the piston 14 andthe carrier 26 and it urges the piston 14 towards the open end 25a ofthe pump body. The piston is held inside the pump body 25 by a metal cap27 crimped onto the pump body and capable of being crimped onto the neckof said tank of fluid.

The pushbutton 1 is mounted on the actuator rod 2. The core 9 and theend wall 10 of the swirling chamber 5 then constitutes the outlet valveof the pump 12.

A second embodiment of a spray nozzle is shown in FIG. 6.Characteristics in common with the first embodiment are not describedagain and are designated by the same reference numerals. The core 9 isnow in the form of a resilient disk made of TPE or of a foam havingclosed cells. The thickness of the disk is small, and may go down to afew tenths of a millimeter. It is wedged between the annular surface 10and the inside face 69 of the end wall 6 which includes the swirlingchannels 8. The disk is thus disposed under prestress in such a mannerthat the channels 8 are completely isolated from one another. Thisresilient prestress also serves to provide good sealing at the annularsurface 10. In the invention, the annular surface 10 has an insidediameter that is larger than the outside diameter of the inside face 6a.Thus, when the fluid is put under pressure in the outlet duct 3, theouter peripheral portion 9a of the disk 9 bends towards the swirlingchamber 5, as shown in dashed lines in FIG. 6. Contact between the diskand the annular surface is thus broken, thereby establishing a passagefor the fluid under pressure. Unlike the first embodiment where the coredeforms by axial compression, in this case the disk is subjected todeformation by bending. The core (disk) is thus restricted to a mereslice of flexible elastomer.

This type of thin core is particularly adapted for use in nozzles fordispensing gel or cream without spraying. It also makes it possible toprovide nozzles/valves of very small thickness, given its owncompactness.

We claim:
 1. A nozzle for spraying a fluid, the nozzle comprising anoutlet duct (3, 4) for receiving said fluid and opening out into adistribution chamber (5) in the center of an annular surface (10), saiddistribution chamber being closed by an end wall (6) pierced by anoutlet orifice (7) and which includes an inside face (6a) provided withgrooves (8) in communication with the outlet orifice, said distributionchamber being partially filled by a core (9) which extends axiallybetween a front face (9a) close to the end wall and a rear face (9b)remote from the end wall, the core leaving empty at least one lateralpassage (11) putting the grooves into communication with the outletduct, the spray nozzle also comprising a valve adapted to close theoutlet duct except during periods when said fluid is being sprayed, andto open under the effect of fluid arriving in the outlet duct, the coreco-operating with the annular surface to constitute said valve, and saidrear face (9b) of the core bearing with sealed contact against saidannular surface (10), wherein the core is a substantially circularlycylindrical elastomer member which is resiliently and axially compressedbetween the end wall of the distribution chamber and said annularsurface.
 2. A spray nozzle according to claim 1, in which the grooves(8) are oriented in a non-radial manner relative to the outlet orifice(7), said front face (9a) of the core being pressed against the end wall(6), thereby isolating the swirling grooves (8) such that the swirlinggrooves do not communicate with one another between the outlet orificeand said at least one lateral passage (11) left empty by the core (9),in order to impart swirling motion to said fluid.
 3. A spray nozzleaccording to claim 1, in which the front face (9a) of the core includesa projecting portion (9c) which penetrates into the outlet orifice (7).4. A spray nozzle according to claim 1, in which said annular surface(10) is conical, with a concave side thereof facing the core (9), andthe rear face (9b) of the core is circular.
 5. A spray nozzle accordingto claim 1, in which said annular surface (10) is a sealing ridge (30)disposed close to an outside of the rear face (9b) of the core.
 6. Aspray nozzle according to claim 1, in which the core is molded inthermoplastic elastomer (TPE).
 7. A spray nozzle according to claim 1,in which centering means (18) are provided for positioning the core (9)relative to the outlet duct (3, 4) and to the outlet orifice (7).
 8. Aspray nozzle according to claim 1, in which the core is a disk (9) thatis elastically deformable by bending, and that is prestressed betweenthe annular surface (10) and the end wall (6), the annular contact ofsaid disk with the annular surface (10) being of a diameter that islarger than the diameter of the contact of the disk with the end wall(6) such that the pressure exerted by the fluid inside the outlet duct(3, 4) deforms the disk by bending its peripherally outer portion,thereby breaking contact with the annular surface.
 9. A spray nozzleaccording to claim 1, in which the core is of narrowed section at anintermediate position (24) along its axial length.
 10. A fluid sprayercomprising a spray nozzle according to claim 1, and a pump (12) whichcomprises:a cylindrical pump chamber (13); a piston (14) which slides inthe pump chamber; an inlet orifice (15) which communicates with the pumpchamber (13) via an inlet valve (16, 17); and a delivery duct (2a) whichis permanently in communication with the outlet duct (3, 4) of the spraynozzle.
 11. A sprayer according to claim 10, in which the piston (14) iscontrolled by an actuator rod (2) in which the delivery duct (2a) isformed, the pump including a spring (19) exerting a return force on thepiston (14), and a pushbutton (1) is mounted on the actuator rod (2) tomove the piston against the force of the spring (19), the pushbutton (1)including said spray nozzle.